#include <chrono>
#include <iostream>
#include <vector>

class RaiiTimer {
   public: 
      RaiiTimer()
      {
         std::cout << "-------" << std::endl;
         b = std::chrono::steady_clock::now();
      }
      ~RaiiTimer()
      {
         std::cout << std::chrono::duration<double>
            ( std::chrono::steady_clock::now() - b).count()
            << std::endl;
      }
   private:
      std::chrono::time_point<std::chrono::steady_clock> b;

};

int main()
{
   std::vector<std::string> v1;
   std::string x = "ABC123";
   for(int i = 0; i < 1000000; ++i)
   {
      v1.push_back(x);
   }

   {
      std::vector<std::string> v2;
      RaiiTimer t1;
      v2 = v1;
   }


   {  
      std::vector<std::string> v3;
      RaiiTimer t2;
      v3 = std::move(v1);
   }

}